A WDM transmission scheme is a known method of transmitting a large capacity of information at a time using a wavelength division multiplexed (WDM) optical signal obtained by multiplexing a plurality of optical signals with different wavelengths. A WDM transmission scheme is used for an optical transmission system such as a financial transaction system or data center system, for example. An optical transmission system with a WDM transmission scheme may adopt an evaluation value for evaluating the quality of services provided by use of channels in a WDM optical signal. Such an evaluation value is called a service level agreement (SLA). A service level agreement includes evaluation values such as availability or delay. Availability is the ratio of the time period for which a WDM optical signal is actually transmitted to the time period for which services are provided by use of channels in the WDM optical signal. Delay is a delay time allowed during transmission of a WDM optical signal.
There is a known technique for applying service restrictions as an SLA to channels in a WDM optical signal in order to ensure resources for channels in a WDM optical signal in an optical transmission system with a WDM transmission scheme, for example, Japanese National Publication of International Patent Application No. 2011-518517 is an example of the related technique.